Cover structure for heat exchanger having resinous tank

ABSTRACT

In a cover structure for restricting adhesion of foreign materials such as an antifreezing agent to a resinous tank of a heat exchanger, a cover member is arranged such that its first end is in the proximity of a boundary between a core portion and the resinous tank of the heat exchanger and its second end is adjacent to an opening through which air is introduced. The cover member blocks the foreign materials entering from the opening and restricts. Also, the cover member directs the air having passed through the opening toward the core portion. Thus, the tank is less likely to deteriorate due to adhesion of the foreign materials. Further, efficiency of heat exchange of the core portion improves.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is based on Japanese Patent Application No.2002-230353 filed on Aug. 7, 2002, the disclosure of which isincorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a cover structure that restrictsadhesion of foreign materials to a resinous tank of a heat exchangersuch as a vehicular radiator.

BACKGROUND OF THE INVENTION

[0003] With regard to a resinous tank of a radiator, the tank is forexample made of nylon 66 (polyamide 66). As shown in FIG. 7, when aradiator 400 having such resinous tank 410 is used in cold regions wherean antifreezing agent is spread, if the antifreezing agent is thrown up,it is likely to pass through a grill 40 and directly adhere to the tank410 as denoted by a thick arrow B. As a result, it causes environmentalstress cracks on the tank 410.

[0004] In order to restrict the environmental stress crack of theresinous tank, for example, it is proposed to blend nylon 12 (polyamide12) and nylon 612 (polyamide 612), which have resistant to theantifreezing agent, with the nylon 66. However, such resistant materialsare generally more expensive than the nylon 66. Thus, it results in anincrease in cost of the radiator. Alternatively, it is proposed toemploy a cover 420 for restricting the antifreezing agent from adheringto the tank 410, as shown in FIG. 8. It also causes an increase in cost.

SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to provide a coverstructure capable of reducing deterioration of a resinous tank of a heatexchanger due to adhesion of foreign materials such as an antifreezingagent.

[0006] According to the present invention, a cover structure is appliedto a heat exchanger that has a resinous tank and, a core portion forperforming heat exchange. The heat exchanger is arranged adjacent to anopening through which air is introduced. A cover member includes a wallhaving a first end and a second end opposite to each other. The covermember is disposed such that the first end is adjacent to a boundarybetween the core portion and the tank and the second end is adjacent tothe opening so that air passing through the opening is directed towardthe core portion.

[0007] Accordingly, the wall blocks and restricts the foreign materialsfrom adhering to the tank. Therefore, the tank is less likely todeteriorate due to the foreign materials. Further, since the air isintroduced toward the core portion along the wall, efficiency of heatexchange improves. Thus, it is possible to reduce the size of the heatexchanger.

[0008] Preferably, the cover structure is employed in a front end of avehicle. Especially in cold regions where the antifreezing agent isspread on roads, the cover member restricts the antifreezing agent fromadhering to the tank. Thus, it reduces environmental stress cracks onthe resinous tank.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Other objects, features and advantages of the present inventionwill become more apparent from the following detailed description madewith reference to the accompanying drawings, in which like parts aredesignated by like reference numbers and in which:

[0010]FIG. 1 is a cross-sectional view of a cover for explaining anarrangement of the cover on a vehicle according to the first embodimentof the present invention;

[0011]FIG. 2 is a perspective view of the cover according to the firstembodiment of the present invention;

[0012]FIG. 3 is a cross-sectional view of the cover and a frameaccording to-a modification of the first embodiment;

[0013]FIG. 4 is a cross-sectional view of a cover and a tank of a heatexchanger according to the second embodiment of the present invention;

[0014]FIG. 5 is a perspective view of the cover and the tank accordingto the second embodiment of the present invention;

[0015]FIG. 6 is a cross-sectional view of the cover and the tankaccording to a modification of the second embodiment of the presentinvention;

[0016]FIG. 7 is a schematic cross-sectional view of a front portion of avehicle for explaining entering of an antifreezing agent of a relatedart; and

[0017]FIG. 8 is a schematic cross-sectional view of a front portion of avehicle and a cover fixed to a tank of a heat exchanger of a relatedart.

DETAILED DESCRIPTION OF EMBODIMENTS

[0018] Embodiments of the present invention will be describedhereinafter with reference to drawings.

[0019] In the first embodiment, a cover structure that restricts foreignmaterials is employed for a radiator, which is generally mounted .in afront portion of a vehicle., As shown in FIGS. 1 and 2, a cover (covermember) 100 is used as the cover structure for a radiator 200.

[0020] The radiator 200 cools a coolant of an engine (not shown). A coreportion 220 of the radiator 200 is constructed of a stack of tubes andfins. The core portion 220 performs heat exchange between air and thecoolant. A core plate 221 is interposed between the core portion 220 anda resinous tank 210. The tank 210 is clamped with the core plate 221.The tank 210 is formed of nylon 66 (polyamide 66) that includes apredetermined amount of glass fiber as a reinforcing agent.

[0021] As shown in FIG. 1, the radiator 200 is mounted on a rear side ofa grill 10, which forms an opening through which a cooling air isintroduced, in an engine compartment 5. The radiator 200 is fixed to avehicular frame (fixing member) 20 having substantially a U-shapedcross-section. A condenser 300, which is a heat exchanger for a coolingapparatus, is provided between the grill 10 and the radiator 200.

[0022] The cover 100 is made of resin such as polypropylene. As shown inFIG. 2, the cover 100 is formed with a cover portion (wall) 110 in aform of plate and two fixing portions 120. The fixing portions 120substantially perpendicularly protrude from the cover portion 110.Fixing holes 121 are formed in substantially middle position of thefixing portions 120. Clips 130 are inserted to the fixing holes 121 andfurther engaged with holes 21 formed on the frame 20, so the cover 100is fixed to the frame 20.

[0023] The clip 130 has stoppers in the form of parasol at its top end.Also, the clip 130 is formed with slit in its central portion along itslongitudinal direction. Therefore, the clip 130 is elasticallydeformable during the insertion and is snapped into the holes 121, 21with a single motion.

[0024] The cover 110 has generally a plate shape extending in alongitudinal direction of the tank 210. The cover 100 is arranged suchthat the cover portion 110 extends between the grill 10 and the coreplate 221. Specifically, a first side 111 is arranged adjacent to thecore plate 221, which defines a boundary between the tank 210 and thecore portion 220. A second side 112, which is opposite to the first side111, is arranged adjacent to the top end of the grill 10. The cover 100is arranged such that distances between the core plate 221 and the firstside 111 and between the core plate 221 and the second side 112 areminimized.

[0025] While the vehicle is driven on roads on which an antifreezingagent is spread for example in cold regions, if the antifreezing agentis thrown up, the antifreezing agent is likely to enter the enginecompartment 5 from the grill 10, as denoted by a thick arrow A inFIG. 1. In this case, because the cover portion 110 blocks theantifreezing agent, it is less likely that the antifreezing agentdirectly adhere to the resinous tank 210. Therefore, the cover structurereduces environmental stress cracks on the resinous tank 210 due toforeign materials such as the antifreezing agent. Accordingly, it is notrequired to blend resistance materials with the resin of the tank 210.

[0026] Since the cover 100 is made of polypropylene, water absorption ofthe cover 100 is lower than that of the tank 210 made of nylon.Therefore, the cover 100 is less likely to cause the environmentalstress cracks even if the antifreezing agent adheres to the cover 100.

[0027] In addition, since the cover portion 110 is arranged to extendfrom the proximity of the core plate 221 to the grill 10, it functionsas a duct for directing the cooling air toward the core portion 220.Thus, the cover portion 110 restricts the cooling air from passing overthe tank 210 (as denoted by a dotted arrow in FIG. 8). Also, the coverportion 110 is disposed such that it does not obstruct the core portion220. Accordingly, the cooling air passing through the grill 10 iseffectively applied to the core portion 220, thereby improvingefficiency of heat exchange of the radiator 200. With this, it ispossible to reduce the size and further cost of the radiator 200. By thecost reduction of the radiator 200, expense of the cover 100 can beoffset.

[0028] The radiator 200 generally has a second tank (not shown) throughwhich coolant flows at its bottom. When the radiator 200 is arrangedsuch that the tank (first tank) 210 is on the top of the core portion220 and the second tank is on the bottom, a temperature of the coolantflowing in the first tank 210 is higher than that of the coolant flowingin the second tank. Therefore, the first tank 210 is in an environmentthat easily causes environmental stress cracks; as compared to thesecond tank. In a case that the cover structure is applied to the toptank 210 of the radiator, it effectively reduces damage to the tank 210.

[0029] As a modification of the first embodiment, protrusions 122, whichcorrespond to the clips 130, are formed in the fixing portions 120. Asshown in FIG. 3, the protrusions 122 have shapes similar to the clips130 so that the protrusions 122 are engaged to the holes 21 or hollowsof the frame 20. Since it is not required to form the clips 130separately, a manufacturing cost reduces.

[0030] In the second embodiment, the cover 100 is directly connected tothe tank 210. As shown in FIGS. 4 and 5, the tank 210 has protrusions211, which correspond to the clips 130 of the first embodiment. Thecover 100 is fixed by engaging the protrusions 211 in the holes 121 ofthe fixing portions 120.

[0031] Accordingly, it is possible to mount the radiator 200 on thevehicle after the cover 100 is fixed to the tank 210. Also, it ispossible to fix the cover 100 to the radiator 200 after the radiator 200is mounted on the vehicle. Thus, assemblability of the cover structureimproves. Further, this is suitable in a case that the frame 20 has lessspace for fixing the cover 100.

[0032] As a modification of the second embodiment, protrusions 122corresponding to the clips 130 of the first embodiment are integrallyformed in the cover 100. As shown in FIG. 6, fixing holes 212 engagingwith the protrusions 122 are formed in a wall that is provided as a partof the tank 210. The cover 100 is fixed to the tank 210 by engaging theprotrusions 122 with the fixing holes 212.

[0033] In the first embodiment and the second embodiment, the coverstructure is used for the radiator 200, which cools the engine coolant.However, the cover structure of the present invention can be used foranother heat exchanger having a resinous tank, which is located on therear side of the grill 10, such as an inter cooling device.

[0034] It is not always necessary that the hole, which engages with theprotrusion for fixing the cover 100, is a penetrated hole. It can be ahollow or depression as long as provides an engagement with theprotrusion.

[0035] The present invention should not be limited to the disclosedembodiments, but may be implemented in other ways without departing fromthe spirit of the invention.

What is claimed is:
 1. A cover structure for a heat exchanger, which islocated adjacent to an opening through which air is introduced and has acore portion for performing heat exchange and a resinous tank connectedto the core portion, the cover structure comprising: a cover memberincluding a wall that has a first end and a second end opposite to eachother, wherein the cover member is disposed such that the first end isadjacent a boundary between the core portion and the tank and the secondend is adjacent to the opening so that the wall directs the air passingthrough the opening toward the core portion.
 2. The cover structureaccording to claim 1, wherein the cover member is fixed to a frame thatsupports the heat exchanger.
 3. The cover structure according to claim2, wherein the cover member has a protrusion and the frame is formedwith a hollow, wherein the cover member is fixed to the frame byengagement of the protrusion and the hollow.
 4. The cover structureaccording to claim 2, wherein the cover member is formed with a hollowand the frame has a protrusion, wherein the cover member is fixed to theframe by engagement of the protrusion and the hollow.
 5. The coverstructure according to claim 1, wherein the cover member is fixed to awall of the tank.
 6. The cover structure according to claim 5, whereinthe cover member has a protrusion and the wall of the tank is formedwith a hollow, wherein the cover member is fixed by engagement of theprotrusion and the hollow.
 7. The cover structure according to claim 5,wherein the cover member is formed with a hole and the wall of the tankhas a protrusion, wherein the cover member is fixed by engagement of theprotrusion and the hollow.
 8. The cover structure according to claim 1,wherein the tank is located on the top of the core portion and thesecond end of the wall is located adjacent to a top end of the opening.9. The cover structure according to claim 1, wherein the tank is made ofnylon
 66. 10. The cover structure according to claim 1, wherein thecover member is disposed such that the wall restricts foreign materialspassing through the opening from adhering to the tank.
 11. A front endstructure of a vehicle comprising: a grill provided at a front end ofthe vehicle, wherein the grill defines an opening through which air isintroduced; a heat exchanger located adjacent to the grill in an enginecompartment, wherein the heat exchanger has a core portion forperforming heat exchange between the air and a fluid flowing inside ofthe core portion, and a tank connected to an end of the core portion;and a cover member including a wall, wherein the wall is disposed suchthat its first end is adjacent to a boundary between the core portionand the tank and its second end, which is opposite to the first end, isadjacent to an end of the opening, so that the cover member directs theair passing through the grill toward the core portion and restrictsforeign materials from adhering to the tank.
 12. The front end structureaccording to claim 11, wherein the heat exchanger is supported in anengine compartment by a frame, and the cover member is fixed to theframe.
 13. The front end structure according to claim 11, wherein thecover member is formed with a fixing portion extending from the wall andthe fixing portion is fixed to a wall of the tank.
 14. The front endstructure according to claim 11, wherein the tank is made of nylon 66.15. The front end structure according to claim 11, wherein the tank isconnected to a top end of the core portion and the second end of thewall is adjacent to a top end of the opening.